<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width,initial-scale=1.0,user-scalable=no">
    <title>smiledemo</title>
    <!--ipone 5 1rem=16px html font-size=16px-->
  </head>
  <body>
    <div id="app"></div>
    <!-- built files will be auto injected -->
  <script >
        let htmlwidth=document.documentElement.clientWidth||document.body.clientWidth;
        let htmlDom=document.getElementsByTagName("html")[0];
        if(htmlwidth>750){
           htmlwidth=750
        }
        htmlDom.style.fontSize=htmlwidth/20+'px';
  </script>
  </body>
</html>
